Anhydrous monocalcium phosphate is a well known composition useful as a baking acid in applications where a delayed or secondary release of carbon dioxide is required. Anhydrous monocalcium phosphate has a theoretical loss on ignition at 800.degree.C. of 15.4 percent. Commercially available anhydrous monocalcium phosphate usually has a loss on ignition at 800.degree.C. between about 14 and about 15.5%.
Monocalcium phosphate monohydrate is a well known composition useful as a baking acid in baking powders and self rising flour compositions. The material is particularly useful in that it provides a relatively fast release of carbon dioxide during the baking process. Monocalcium phosphate monohydrate has a loss on ignition of 20.5%. Commercially prepared material usually has a loss on ignition between about 20.0 to about 21.5%.
Although the product, monocalcium phosphate monohydrate has been used extensively, the material is known to cake badly on storage. It is the custom to introduce additives into the product to prevent lumps from forming in bags on storage or on exposure to a humid atmosphere. Conditioning agents as disclosed in U.S. Pat. Nos. 1,913,796, 3,244,478, 3,273,960 and 3,678,883 have been developed to prevent caking of the monocalcium phosphate monohydrate during storage.
Another method employed to improve the caking tendencies and flow properties of monocalcium phosphate monohydrate involves milling of the wet crystals before drying. The process improves the properties of the composition, but requires careful control and is a high maintenance process with a low onstream factor.
It is an object of the present invention to provide a method for preparing a hydrated monocalcium phosphate composition with reduced caking tendencies. It is a further object of the present invention to provide a method for preparing a hydrated monocalcium phosphate composition having reduced caking tendencies without the addition of additives. Another object of the present invention is to provide a monocalcium phosphate composition with reduced caking tendencies which has the quick carbon dioxide release characteristics of monocalcium phosphate monohydrate.